FWIW language gives children a tool with which they can discuss and more importantly reason about abstract concepts. The sooner you acquire a rich and varied vocabulary the sooner you can form a rich understanding about the phenomena in the world around you. Since kids learn fastest when they are young and that slows with age, a strong grasp of language means that they can absorb and understand more abstractions sooner. Measures of betweenness, distance, centrality and distance for nodes in a child's mental graph of abstractions are all likely to be better when you have a richer vocabulary at a young age. Even edges between abstractions can be linguistic abstractions like similes and metaphors, giving a child a quickness in recall of well understood abstractions to aid in the processing and understanding of novel concepts.